Device for timing magnetos to operate with two-cylinder gas-engine set v-shaped.



T. M. MUELLER. DEVIUE FOB TIMING MAGNETOB TO OPERATE WITH TWO CYLINDERGAS ENGINES BET V-SHAPEDc APPLICATION rum) 00112, 1907.

964,298. Patented July 12, 1910.

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UNITED STATES PATENT OFFICE.

THEODOR M. MUELLER, OF BRAINTREE, MASSACHUSETTS.

DEVICE FOR TIMING MAGNETOS TO OPERATE WITH TWO-CYLINDER GAS-ENGINES SETV-SHAPED.

T 0 all whom it may concern:

Be it known that I, Trmooon M. MUELLER, a subject of Germany, residingat Braintree, in the county of Norfolk and State of Massachusetts, haveinvented an Improvement in Devices for Timing Magnetos to Operate with Two-Cylinder Gas-Engines set V-Shaped, of which the followingdescription, in connection with the accompanying drawings, is aspecification, like numerals on the drawings representinglike parts.

In running two-cylinder gas engines in connection with a magneto,difliculty is commonly experienced in getting proper etliciency from themagneto, due to the fact that the cylinders of the engine are set V-shape or at an angle of less than 180 degrees, whereas, "the poles ofthe magneto being 180 degrees apart, the sparking of the magnetocon'nnonly takes place at equal intervals, i. 6., 180 degrees apart,which does .not correspond to the angle ot the cylinders; and.accordingly my invention aims to provide means for synchronizing themovement of the magneto to correspond to the relative position of saidtwo cylinders which are set V-shape, so that the spark will be producedby the magneto at exactly the correct time for each of the cylinders andat the time the current is at its maximum. To this end I interposebetween the armature shaft of the magneto and the driving gear thereof,means for converting the uniform rotation of the latter into alternatelyaccelerated and retarded movement of the arn'iature, the result beingthat there is a long inter 211 between two successive interruptions ofthe primary current of the magneto and then a short interval, saidintervals corresponding to the cycles of movement of the engine anddepending upon the angle of the two cylinders.

\Vhile my invention may be carried out by a wide variety of i'nechanism,I have herein shown and described only the preferred embodimentsthereof, the drawings showing in, Figure 1 a transverse sectional viewof one embodiment of the invention applied to a usual magneto; Fig. 2 across sectional view on line 22, Fig. 1 showing in end elevation themeans for accomplishing the variable movement; Fig. 3 a similarsectional view showing the parts in another position; and Fig. 41- apartially diagram- Specification of Letters Patent.

Application filed October 12, 1907.

Patented July 12, 1910.

Serial No. 397,120.

matic view of a modification. In Figs. 5, 6, 7 and 8 I have shownsimilar views of further modifications, the latter two being partlydiagrammatic; Fig. 9 is a similar end view, partly diagrammatic,illustrating a further application or modification of the invention; andFigs. 10 and 11 are diagrammatic views representing my invention inoperative relation to the engine.

I have deemed it unnecessary to show the mechanism of the magneto as anykind may be employed, for instance, such as is shown in my Patent No.845,368 Feb. 26, 1907.

As already stated, my invention resides in providing between the engineor source of driving power and the armature of the magneto, means fordriving the latter at varying speeds, such that it will cause theinterruptions of the primary current to take place when the current isat its maximum and when the pistons of the two V-set cylinders are atthe right position respecti vely therefor. Preferably said means isapplied. directly to the magneto, although I wish it understood that itmay be applied at any point between the source of driving power and themagneto whereby the armature of the latter will receive the desiredvariations of speed at the proper moments.

Referring to the diagrammatic Figs. 10 and 11, I have indicated a usualcrank shaft 1 of the engine, having two cylinders 2, 3 containingpistons 4C, 5, whose piston rods 6, 7 are driven by said crank shaft,said cylinders being set V-shape or at an angle to each other less than180 degrees, as is usual in this type of engine. The magneto 8 is shownas driven by a gear 9 fast on its armature shaft 10 and in mesh with theengine cam shaft 11, which in turn is engaged with a gear 12 on thecrank shaft, the armature being indicated at 13. In Fi 10 the parts areshown in the right position of the armature of the magneto for firingcylinder 2, whose piston is then just ready to begin its down stroke. Ifthe armature is driven at uniform speed it is evident that when thepiston 5 of cylinder 3 is in the corresponding position, ready to befired, as shown in Fig. 11, the armature will then be in the positionshown in dotted lines at 14- Fig. 11, whereas for proper efficiency itshould. be in the position shown in full lines in Fig. 11. To retard itsmovement therefore, so that instead of occupying the dotted lineposition it will occupy the full line position Fig. 11 when the cylinder3 is to be tired, and will thereafter be advanced so that when thecylinder 2 is again ready to be tired, the armature will have beenrotated so as to bring it again into the position shown in Fig. 10, Iinterpose at some convenient point between the crank shaft 1 or sourceof driving power, and the magneto armature shaft l0,the variable speedmechanism hereinafter described, which is preferably connected directlyto the armature shaft itself.

Referring to Figs. 1 and 2, I have provided a controller shown as aneccentric cam 15 held stationary by any suitable means as by beingmounted directly on the frame 16 of the magneto, and have mounted thegear 9 loosely on the shaft 10 of the magneto. Between said shaft andgear I interpose a knuckle joint, one link 17 thereof being pivoted at18 to the gear 9 and the other link 19 being pivoted at 20 to an ear 21fast on the shaft 10, said two links 17 and 19 being pivoted together at22 so as to permit them to buckle or bend outwardly as their revolvingforce is being controlled by the eccentric wall or flange of the cam 15.This outward and inward movement of the links causes a shortening orbringing together of the two pivot points 18 and 20 when the pivot istraveling over the short radius side of the eccentric, and causes alengthening or separation of the two pivots 1S and 20 when the pivot 22is traveling over the long radius side of the eccentric, and as thepivot 18 is compelled by the gear 9 to move at an absolutely uniformspeed, the result is that the pivot 20 and hence the armature shaft 10and its armature are compelled to move at a varying speed. The links 17and 19 may be held outward by any convenient means, a spring 23 beingshown in Fig. 4- and a ring 21 being shown in Figs. 2 and 3. The ring 2tconstruction makes it absolutely positive that the varying speed shallbe under the perfect control at all times of the eccentric flange,inasmuch as the ring fitsthe eccentric (therebyrendering this species ofcam preferable) and is carried around by a pin 25 projecting from an ear26 of the link 19. said pin 25 being outside of the pivot 22 as shown inFigs. 2 and 3. Fig. 2 corresponds in the position of parts to thediagrammatic View in Fig. 10, and Fig. corresponds to Fig. 11.

In Figs. 5-8 I have shown a modification of the previously describedconstruction, in which a link 27 is pivoted as before at 28 to the gear9 and is pivotally connected at 29 to a link 30, which isintern'iediately pivoted at 31 to an arm 32 projecting rigidly out fromthe armature shaft 10, the free end of said link 210 being pivoted at 34to a sliding ring 35 mounted on a stationary eccentric 36 whichsurrounds the armature shaft 10. The ring 35 may be omitted and a.spring 37 employed, as shown in S, performing the same office as thespring in Fig. -t. The parts are shown n Fig. 5 in the positioncorresponding to Fig. 10, and in Fig. 6 corresponding to Fig. 11. InFig. 7 I have shown diagranunatically the mechanism in the same positionas in Fig. 6 for the purpose of illustrating the operation of thedevices somewhat more clearly.

For the purpose of making more apparent the fact that my invention neednot be applied necessarily directly to the armature shaft but may beinterposed at any other place between the source of driving power andsaid armature shaft, I have indicated in Fig. 9 the variable speedmechanism as pivoted at 38 to a gear 39 loose on a shaft -l-() which hasfast thereon a second gear 41, the latter being in mesh with the gear f)and the former. gear 3!) being in mesh with gear 11. This view isinserted simply to make clear the breadth of my invention. In Fig. 1 Ihave indicated the primary winding at 42, the secondary winding at- 1:3,and the collector ring at at, the brushes being shown at t5, 4th, inFig. 11, whence the conductor wires ti, l8 connect to the spark plugit), of the engine cylinders 2, 3. respectively.

r\s I haveah'eadybrieflydescribed the operation in connection with mydescription of the details of construction, and accordingly it will besufficient to point out in each instance that as the engine, through itstrain of gears, drives the magneto gear forward at an even, continuousspeed, the latter, through the pivot pin 18 or 28 as the case my be,moves the link 17 or 27 for ward at the same even speed, but as saidlink and its connected link 19 or 30 is caused by the adjacent eccentricto move alternately toward and from the magneto shaft and therebycorrespondingly advance and retard the car 21 or arm 32, the result isthat the magneto shaft (which fixedly carries said ear or arm) and itsarmature, are correspondingly advanced and retarded. This advancementand retardation are so arranged with relation to each other that theycause the armature to l)10t k the magneto circuit at the same point orposition with relation to their pole pieces for firing each of the twocylinders 2, 3 notwithstanding the fact that the latter are set'V-shapewith relation to each other. In other words, the magneto current isinterrupted at its maximum for both cylinders when their pistons are inthe same position respectively. By reason of my invention it is nolonger necessary to tire cylinder 2 a little prior to the arrival of itspiston 4- at the most desirable point therefor and to fire cylinder 3 alittle after the arrival of its piston 5 at the most desirable pointtherefor, due to the fact that the magneto was driven at the sameunvarying speed as the engine and hence its current was interrupted atpoints corresponding to successive positions of the crank shaft 180degrees apart, but because of the variable speed mechanism interposedbetween the magneto and the crank shaft, the latter is automaticallyretarded and advanced so as to interrupt the magneto current when thecrank shaft is in corresponding positions for each of the two V-setcylinders. I prefer to employ the eccentric as it gives uniformacceleration and retardation to permit the employment of theposition-maintaining rings 2st, 35, but I do not intend to limit myselfto this form of cam surface or controller nor to this form ofposition-maintainer, and it will be understood also that the form of thecam surface of path controller will depend upon the angle of thecylinders.

Having described my invention, what I claim as new and desire to secureby Letters Patent is,

l. The combination with a magneto and its armature and a gas-enginehaving V- set cylinders, of a driving gear, connections from said gearto said armature including means having an unvarying movement withrelation to the armature, and yielding mech anism between said means andsaid gear to similarly position the tll'llltLt-IUTQ at the explodingmoments of said cylinders respectively, and a cam for determining thevariations of said yielding mechanism and thereby controlling theresulting variable speed of the armature with relation to said gear.

2. The combination with a magneto and its armature shaft and agas-engine having V-set cylinders, of a driving gear, yieldingconnections between said gear and said shaft for timing the movements ofthe armature to the positions of the pistons in said cylinders, a camfor determining the variations of said yielding connections, and

1 means cooperating with said cam and said yielding connections forcompelling the latter to be governed at all times by the cam.

3. The combination with a magneto and its armature shaft, of drivingmeans, yielding connections between said driving means and said shaft,an eccentric for determining the variations of said yieldingconnections, and a slide ring cooperating with said eccentric and saidyielding connections for compelling the latter to be governed at alltimes by the eccentric.

4:. The combination with a magneto and its armature shaft, of a drivinggear loose on said shaft, links pivotally connected to each other andone link being pivoted to said gear, the other link being pivoted tosaid shaft, said links being capable of moving radially toward and fromsaid shaft at their intermediate pivotal connection, and a cam forgoverning said radial movement and thereby producing, through the links,forward and backward movement of the shaft with relation to the gear.

5. The combination with a magneto and its armature shaft, of a drivinggear loose on said shaft, links pivotally connected to each other andone link being pivoted to said gear, the other link being pivoted tosaid shaft, said links being capable of moving radially toward and fromsaid shaft at their intermediate pivotal connection, a. cam forgoverning said adial movement, and sliding means connected to said linksand maintained at all times in sliding engagement with said cam, therebyproducing, through the links, forward and backward movement of the shaftwith relation to the gear.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

THEODOR M. MUELLER.

Witnesses ANNIE I. WALKER, JOHN F. TROY.

